1. Field
The present disclosure generally relates to fluid transportation. More particularly, the present disclosure relates to a guided fluid transport method and devices by use of a patterned array of nanofibers or nanotubes. Patterned fibrous mats are formed from aligned carbon nanotube arrays having porous interstices to conduct liquid flow, wherein the porous interstices provide both the driving forces for the flow and functions such as sieving, diverging, and filtration.
2. Related Art
Three thousand years ago, people invented a wick to draw controllable amounts of fuel liquid up through the wick material, against the flow of gravity, to burn at a constant rate at the tip of the wick. In textile research, wicking is the process by which liquids are transported across or along fibers by capillary action (of relevance to perspiration). The applicants recently observed a similar phenomenon with mats of carbon nanotube fibers. Under the aid of a surfactant, the solution not only penetrates into but also flows on the ultra-hydrophobic carbon nanotube mat due to wetting forces and the Marangoni effect. Scientists have been working for about 20 years on fluid wicking circuits, typically called Capillary Pumped Loops (CPL) or Loop Heat Pipes (LHP). Those applications are limited to microscale tubes.
U.S. Pat. No. 6,685,810, also incorporated herein by reference in its entirety, relates to a biomolecular sieve based on carbon nanotube arrays.
U.S. patent application Ser. No. 11/124,523 filed on May 5, 2005 for “Capillary Lithography of Nanofiber Arrays,” also incorporated herein by reference in its entirety, discusses the wetting/drying machining-nesting process (capillo-lithography) to postmanipulate patterned CNT arrays in order to produce different surface morphologies. Experiments with carbon nanotube mats have shown that wetting and drying of the mats results in reorientation of the nanotubes into particular formations. Some groups of the carbon nanotubes go from being mostly vertical and aligned with each other to being pulled apart from each other, either radially or linearly, leaving semi-circular or trench-like formations. The shape is like that of a nest, and these structures are referred to as “nests” in the '523 application. These nests have been observed to form upon drying of wetted carbon nanotube mats. According to the present disclosure, these surface morphology changes will be used to control of flow.